Performance of Ferrite‐Based Electrodes for Steam Electrolysis in Symmetrical Solid Oxide Cells

Abstract

AbstractThere is an increasing interest in the exploration of non‐Nickel cathode materials for steam electrolysis in solid oxide electrolysis cells (SOEC) for green hydrogen production with high Faradaic efficiencies. Ferrite‐based ceramic materials have drawn a lot of attention in this regard due to their appreciable mixed ionic electronic conductivity. This work aims to explore a ferrite‐based mixed ionic electronic conductor electrode for symmetrical SOEC that can contribute significantly to simplifying the manufacturing processes. A composite of silver (Ag) and A‐site deficient lanthanum strontium cobalt ferrite ((La0.60Sr0.40)0.95Co0.20Fe0.80O3‐x), is studied for steam electrolysis in a yttria stabilized zirconia electrolyte‐supported symmetrical tubular solid oxide cell. A considerable current density of 250 mA cm−2 is obtained at 1.5 V and 800 °C in a Helium‐Steam atmosphere (50% humidified) with a corresponding polarization resistance as low as 0.15 Ω‐cm2. The polarization resistance is comparable to a number of electrodes reported in the literature for steam electrolysis. However, a 10% drop in current density is observed during the first 20 h of electrolysis at 1.5 V and 800 °C in a Helium‐Steam atmosphere (50% humidified), but no further drop is encountered during the next 46 h of continuous operation.